Niu et al. previously found that uninsured and Medicaid-insured patients with breast, cervical, colorectal, head and neck, lung, prostate, or uterine cancer have higher mortality rates compared to patients with private insurance or Medicare. Because substantial proportions of the U.S. population continue to be uninsured or enrolled in Medicaid, this may become more relevant as an equitable distribution of health was one of the aims for improvement in the Institute of Medicine’s 2001 report.

In this analysis, adult female admissions with a primary diagnosis of breast cancer between 1999 and 2014 were extracted from the National Inpatient Sample database using the ICD-9 code 174.9 (n = 98,631, for a weighted n = 484,859). To minimize the effect of changes in mortality rates based on insurance status over the time interval studied, the researchers grouped the admissions into three categories: group 1 for admissions from 1999–2003, Group 2 for 2004–2008, and Group 3 for 2009–2014.

Admissions were higher for those with Medicare or private insurance, and mortality was highest for self-pay or uninsured, followed by Medicaid (see Tables 1 and 2). Even after controlling for age, race, median income, and comorbidities, the hazard of death was significantly higher in the Medicaid and self-pay/uninsured groups.

Table 1. In-Hospital Mortality (%) by Primary Payer

Year Group

Medicare

Medicaid

Private Insurance

Self-Pay/Uninsured

p

1

3.83

6.77

3.43

10.14

0.0001

2

4.58

7.55

4.95

9

0.0001

3

2.84

3.46

3.02

10.26

0.0001

Table 2. Hazard Ratio of Death During Hospitalization

Year Group

Medicaid Versus Medicare

p

Uninsured Versus Medicare

p

1

2.03 (1.49, 2.76)

0.0001

3.2 (2.49, 4.22)

0.0001

2

1.56 (1.19, 2.46)

0.0001

2.9 (2.20, 3.80)

0.0001

3

2.55 (1.99, 3.27)

0.0001

7.76 (1.99, 3.27)

0.0001

The results suggest that the Institute of Medicine’s goals are not yet being achieved, but the group added that more scientific research is needed in the area of differential receipt of standard therapy in patients with cancer.